Power strapping machine and the like and adjustable feeding and tensioning means therefor



H. K. OTTO 3,272,113 HINE AND THE LIKE AND ADJUSTABLE TENSIONING MEANSTHEREFOR Sept 13, 1966 5 Sheets-Sheet 1 POWER STRAPPING MAC FEEDING ANDFiled Dec. .14, 1964 NvENToR HOWARD K. OTTo AT'rYS.

H. K. oTTo 3,272,113

ADJUSTABLE SIGNING MEANS THEREFOR Sept. 13, 1965 POWER STRAPPING MACHINEAND THE LIKE AND FEEDING AND TEN Sheets$heet 2 Filed Dec. 14, 1964INvEN'roR Howmw O'r'ro M {M 3272 113 STABLE H. K. OTTO HINE AND TH Sept.13, 3966 E LIKE AND ADJU ENSIONING MEANS THEREFOR POWER STRAPPING MACFEEDING AND T 5 fiheets-Sheet 5 Filed Dec. 14, 1964 United States PatentPOWER STRAPPHNG MACHINE AND THE LIKE AND ADJUSTABLE FEEDING ANDTENSIUNIN G MEANS THEREFOR Howard K. Gtto, Berkeley, 11]., assignor toSignode Corporation, Chicago, 111., a corporation of Delaware lFiledDec. 14, 1964, Ser. No. 418,039

18 Claims. (Cl. 100-46) The present invention relates to power strappingmachines for binding bundles, packages, coils and similar articles withloops of flat tensioned straps and the like with overlapping ends unitedin a tension resisting joint. Particularly, the invention relates to apower strapping machine of the class described wherein the pressure withwhich the strap is gripped by the machine is controlled in accordancewith the tension in the strap during the feeding and tensioning of thestrap.

Machines of the class referred to herein operate automatically orsemi-automatically to pass a length of strap about a bundle with thefree end of the strap placed in overlapping position with the standingportion thereof. The standing portion of the strap is that partconnected to a source of strap supply such as a reel or coil thereof.The free end of the strap is gripped and then the standing portion iswithdrawn so that the loop of strap is shrunk closely down about thebundle as a proper or selected tension is applied thereto by themachine. When the tension has reached a satisfactory value, theoverlapping portions of the strap and an embracing seal are crimpedtogether and united into a tension resisting joint; and the strapapplied to the bundle is severed from the source to provide a strappedarticle.

In a machine of the described class, the operations of feeding orpassing of the strapping segment about the bundle and thereaftertensioning the strap employ the same components which are driven indifferent directions to perform the two functions. Generally employedfor the purpose are a pair of opposed wheels between and by which thestrap is fed in one direction into binding position and by which thestrap is pulled in an opposite direction for tensioning same.

During the tensioning operation, at least one of the wheels positivelydraws the strapping by frictional engagement thereof or by biting thestrapping with peripheral teeth. In the course of each strap tensioningoperation as the strap segment about the bound article shortens, therequirement for torque to pull or tension strap gradually increases asthe resistance to the tensioning gradually increases. Therefore, it isdesirable to have applied to the strap a gradually increasing force ofsufficient magnitude to overcome the increasing resistance to thetensioning until the desired tension level is reached.

With prior devices, frequently, before desired tension is achieved, theresistance in the applied strap to the pulling in reverse feed ortensioning direction by the opposed wheels becomes greater than thetorque applied frictionally to pull the strap. As a consequence of theforegoing, any wheel driven to tension the strapping will have atendency to slip with a consequent undesirable erosion of the strap andof bearings of the shaft providing an axis of rotation for each drivenwheel.

The instant invention overcomes this problem and provides a new andimproved strapping machine adapted automatically and gradually to adjustthe pulling force on the strap in proportion to the increase inresistance therein during tensioning. To accomplish this, machinesembodying this invention are provided with an improved feeding andtensioning mechanism which incorporates a driven eccentric adapted tomultiply the torque of the prime mover and enhance the force with whichthe strapping being tensioned is gripped between the wheels.

3,272,113 Patented Sept. 13, 1966 These and other features andadvantages of the present invention will become apparent uponconsideration of the following description and appended claims, whenconsidered in conjunction with the accompanying drawings, which form apart of this specification, wherein the same reference character ornumeral refers to like or corresponding parts throughout the severalviews, and in which:

FIGURE 1 is a side elevational view of a power strapping machineembodying the improved feeding and tensioning mechanism;

FIG. 2 is an end view of one embodiment of the improved feeding andtensioning mechanism, with parts broken away to illustrate various otherparts;

FIG. 3 is a sectional view taken substantially on the line 33 of FIG. 2and looking in the direction of the arrows;

FIG. 4 is a sectional view taken substantially on the line 4-4 of FIG. 3and looking in the direction of the arrows;

FIG. 5 is an end view of a modified embodiment of the feeding andtensioning mechanism, with parts broken away to illustrate various otherparts; and

FIG. 6 is a sectional View taken substantially on the line 66 of FIG. 5and looking in the direction of the arrows.

There is illustrated in FIG. 1 a power strapping machine which isprovided with a frame lli on which there is mounted a prime mover meansshown as a reversible electric motor 11 or the like, a motor housingflange 20 of which is suitably secured by fasteners such as bolts 13 tothe frame.

The drive shaft of the motor 11 operably connects with a pinion 12, asillustrated in FIG. 3. On an end portion thereof pinion 12 carries aspiroid gear head 14 for which said pinion provides a fixed axis ofrotation. The pinion 12 is suitably journalled, for example, in ballbearings 15.

Prime mover force is transmitted through the gear head 14 to drive astrap feeding and tensioning mechanism designated generally as numeral16 in FIG. 1. The details of construction of one form of the strapfeeding and tensioning mechanism 16 are shown in FIGS. 2, 3 and 4. Thedetails of construction of a modified form thereof are shown in FIGS. 5and 6.

With respect to the system shown in FIG. 1, mechanism 16 feeds strap Sto the left and tensions strapping S to the right. Strap S passesthrough a pair of path providing guides 17 and 18, each of whichcomprises a pair of spaced apart plates disposed behind a cover plate33. The guide 17 is disposed on the tension side of the mechanism 16 andthe guide 18 is disposed on the feed side of mechanism 16.

The strap S is fed during operation of the power strapping machine fromguide 18 and through a closed guide, track or chute 19 about a thereinprovided bundle receiving opening 21. The guide, track or chute 19provides a path directing the leading edge S of the strap intooverlapping relationship with the standing portion S" of the strapadjacent the joint-forming mechanism not clearly shown in the drawings.

In the illustrated machine there is provided an abutment 23 againstwhich the leading edge S of the strapping is guided to stop furthermovement thereof. When this happens, the feeding drive of the motor 11continues, but track 19 is provided with a spring biased drop-outsection or jaw 24 so that the fed strap which can no longer advance willbuild up force in chute 11. That will cause jaw 24 to ultimately pivotagainst action of its spring 23 to permit the excess strapping toballoon outwardly, as illustrated in dotted lines in FIG. 1.

As the jaw of drop-out section 24 pivots downwardly it engages androtates a spring biased plate 25 into engagement with lever 26 of switch27. Switch 27, which is suitably mounted upon an accessible portion ofthe frame in any conventional manner, is operably connected to thereversible motor 11. When the switch lever 26 is moved under the actionof the depressed plate 25, as aforedescribed, the motor 11 reverses itsdrive to begin the tensioning operation.

As the tensioning operation progresses, that is, as S moves to the rightwith respect to FIG. 1, the ballooned strap section will be returned tochute 19; and under the action of spring 28, jaw portion 24 will beurged back to its normal track position.

At the conclusion of the tensioning operation the jointforming operationoccurs. A seal is applied about the overlapped leading edge S andstanding portion S", and when the tensioning operation has beencompleted the seal is crimped about such overlapped strapping.

To the end that a seal will be formed by the machine, an open ended sealmagazine 29 therewithin adapted to hold a plurality of metal seal blanksin stacked fashion is suitably carried upon the frame 10. A followermember 30 urged to the left with respect to FIG. 1 by spring 31 keeps aconstant pressure on the stack of seals in the magazine 29. The exit endof the seal magazine 29 is obscured in FIG. 1 by a bracket 32.

The mechanism for removing the seals one at a time from the magazine 29as well as the mechanism for applying and crimping the seal and forsevering the standing end S of the strap are not shown in detail. Theymay be of any suitable type such as that disclosed in US. Patent No.2,915,003, issued December 1, 1959.

Referring now more particularly to the feeding and tensioning mechanism16, which is shown in detail in FIGS. 2, 3 and 4, attention is invitedto its plate or cover 33 which is secured by appropriate fasteners suchas screws, bolts 34, or the like to an accessible portion of frame 10,and it has a centrally disposed aperture 40. The cover or plate 33 hasan inwardly extending annular flange 35, the outer diameter of which isless than the outer diameter of the plate or ring 33. Accordingly, anannular shoulder 36 is generated which abuts against a fiat surface 37provided by the frame 10. An annular slot 38 provided in the flange atits juncture with or point of departure from the cover of plate 33provides a Well for a sealing or O-ring 39 which seals the plate orcover 33 to the frame member 10, as illustrated in FIG. 3.

There is a bore or opening 41 in the frame 10 into which the flange 35extends. The hub 43 of a spiral or spiroid gear 44 extends toward thecover or plate 33 and is centrally disposed within the bore 41 wherebythe axis of rotation of said gear 44 is coincident with the longitudinalaxis of bore 41. The spiral or spiroid gear 44 meshes with gear head 14to thereby transmit prime mover force to the spiroid gear 44.

The bore or opening 41 is enlarged to provide an annular shoulder 42. Atthe juncture of the spiroid gear ring 44 with its hub 43, an annularshoulder 45 is provided in operative alignment with the shoulder 42. Thealigned shoulders 42 and 45 provide an abutment for the annular race ofa ball bearing 46 in which the hub 43 is journalled. A snap ring 47,which is seated in annular groove 48 formed in the hub 43, acts as aretainer by engaging against the race of ball bearing 46 to hold thesame against the shoulders 42 and 45 in the manner illustrated in FIG. 3of the drawings.

An inwardly disposed annular shoulder 49 is provided by the cover orplate 33. The shoulder 49 provides an abutment for the annular race ofball bearing 50. Ball bearing 50 is spaced from ball bearing 46 andprovides a journal for the inner end portion of the gear hub 43. Ballbearing 50 is retained in abutment with the shoulder 49 by means of aspacer 51, the opposite surfaces of which bear against the facing partsof bearings 46 and 50 in the manner illustrated in FIG. 3.

The spiroid gear 44 and hub 43 thereof have a centra-lly disposedaperture or opening 52. A spur ring gear comprising a plurality ofinternal spur or inwardly extending radial teeth 53, only several ofwhich have been labeled in FIG. 4, are fabricated preferably integralwith the spiral or spiroid gear 44 and extend into opening 52. Teeth 53mesh with the outwardly extending or radial teeth 54 of a planet spurgear 55. The radius of the planet spur gear 55 is less than the radiusof the internal spur ring gear by reason of which the torque transmittedfrom the shaft 12 through the gear 14 through the gear teeth 53 to thegear 55 will tend to drive the planet spur gear 55 eccentrically in thebore or opening 52 in which said spur planet gear is disposed.

The spur gear 55 is integral with or rigidly secured on a stub shaft 56which provides the axis of rotation for the spur planet gear 55. Theaxis of rotation of the stub shaft 56 extends longitudinally of the axisof rotation of spiroid gear 44. However, the disposition of the axis ofshaft 56 is eccentric with respect to the bore or opening 41; and theshaft 56 extends eccentrically through the opening or aperture 40 in thecover or plate 33, for a reason which will be apparent hereinafter.

A toothed traction wheel 57 is rigidly secured on an outer end portion58 of the shaft 56. The securance can be achieved suitably by keying orsplining as shown at 59. Such construction insures rotation of thetraction wheel 57 with the shaft 56.

To preclude outward displacement of the traction wheel 57 longitudinallyof the shaft 56, a removable retaining split clamp or ring 60 is mountedin an annular peripheral groove 61 formed in the outer end portion 58 ofthe shaft 56. An outer peripheral extension 62 of the clamp or splitring 60 extends outwardly from groove 61 and bears against the outer endface 63 of the hub 64 of the toothed traction wheel 57.

The split ring or clamp 60 has a pair of apertured ears or lugs whichare disposed in opposed positions, as illustrated in FIG. 2. By means ofa suitable tool, not shown, the split ring or clamp 60 may be mounted orremoved according to requirements.

To preclude inward displacement of the toothed traction wheel 57longitudinally of the shaft 56, a pair of shoulders 66 and 67 areprovided on the shaft end portion 58 in longitudinally spaced apartrelationship by external diametric reductions. The shoulders 66 and 67are engaged by corresponding interior abutting surfaces formed in thebore 22 of the toothed traction wheel 57, as illustrated to the left inFIG. 3.

The toothed traction wheel 57 has a plurality of integral peripheralteeth 68 which are adapted to bite into the strap S whereby the strap Smay be fed or tensioned according to the direction of the torque appliedon such strap by the traction wheel 57. The traction wheel 57 issubstantially as wide as the strap S whereby there is a maximumapplication of the driving torque to the strap S.

The back up wheel or pressure roller 69 is disposed in operativealignment with the toothed traction wheel 57, as illustrated in FIG. 2.The back up wheel 69 engages the strap S on a side opposite to thetraction wheel 57 to maintain the strap in engagement therewith toinsure that the strap S is fed or tensioned according to the directionor rotation of the shaft 56. The back up wheel or pressure roller 69rotates on a fixed axis of reaction which is provided by shaft 70. Theshaft 70 is suitably journalled in an accessible portion of the frame 10and cover or plate 33.

The shaft 56 is centrally journalled within the passage :or bore 72 of arotor 71. The rotor 71 is itself rotatably mounted in the bore 52. Thebore 72 of the rotor 71 is disposed eccentrically therein as clearlyillustrated in FIGS. 2 and 3.

The means for journaling the rotor 71 which is centrally disposed withinthe bore 52, comprises a pair of needle bearings 73 and 74 which aredisposed longitudinally of the shaft 56 about the rotor 71 against theinner surface of the hub 43. These bearings 73 and 74 are held in spacedapart relationship by means of spacer 75, the opposite annular ends ofwhich bear against facing portions of the races of the bearings 73 and74. At one end the eccentric 71 bears against one face of a washer 76which also serves to prevent displacement of the bearing 73 and 74 byengagement with a portion of the race of bearing 73 in the mannerillustrated in FIG. 3. The opposite face of the washer 76 bears againstan annular shoulder 77 formed at the juncture of the shaft 56 with itsgear 55. The washer is centrally apertured and disposed about the shaft56 in the manner illustrated in FIG. 3.

Longitudinal displacement of the rotor 71 in the direction of thetraction wheel 57 is precluded by means including a rotor flange or cap78. The rotor flange or cap 78 is mounted in the aperture 411 of theplate 33 and it is connected to rotor 71 by means to be hereinafterdescribed. The plate 78 is fabricated from any suitable bearing metalsuch as bronze and the like for a reason which will become apparenthereinafter.

Rotor flange or cap 78 has an eccentrically disposed aperture 79 whichis in longitudinal axial alignment with the bore or passage 72 in therotor 71 whereby said aperture 79 accommodates the shaft 56. An 0 orsealing ring 30 which is mounted in a peripheral annular groove 81 inthe flange 78 acts as a seal of said plate in the mounting cover plate33, as illustrated in FIG. 3. A ring 32 is mounted in an annular recess83 in said flange 78 about the shaft 56 and functions to seal theopening between said flange 78 and sai shaft 56.

The flange 78 has an inner shallow pan-shaped enlarged recess in whichthe outer end portion 84 of the rotor 71 is mounted to bring theadjacent faces thereof into abutment along an apertured flat 85.

Flange 78 on an inner surface is formed with a radial flange 86 which isdisposed against the inner surface of the cover 33 about the opening 40as illustrated in FIG. 3. The height of flange 86 is suflicient toprovide an abutment for the shaft 43 and also for the outer surface ofthe race of bearing 74 whereby displacement of the bearings 73 and 74toward the traction wheel 57 is preeluded.

To journal the shaft 56 there are provided a plurality of annularbearing members 87, only some of which have been numbered in FIGS. 2 and3. The bearing members 37 are spaced from each other longitudinally ofthe shaft 56, and they center the shaft 56 in the apertures 72 and 79.At one end the bearings 87 are retained by engagement with the washer 76as illustrated in FIG. 3; and at the opposite end the bearings 87 areretained from displacement longitudinally of shaft 56 by means of theflat 85 provided by the flange 78.

For further locking the parts from undesired displacement there isprovided a split ring 38. The inner annulus of the split ring 88 isangular in cross section as illustrated in FIG. 3. The ring isaccommodated in a peripheral groove of corresponding angulation which isformed in the shaft 56 adjacent the flange 78 medially thereof and thetraction wheel 57, as shown at $9 in FIG. 3. A split ring or clamp 99having a pair of opposed apertured ears or lugs 91 is mounted in aperipheral slot provided therefor in the split ring 98. By means of aconventional tool, not shown, the ring or clamp 90 can be mounted anddismounted as required.

A rigid lug, base or support 92 is suitably supported on any accessibleportion of the frame of the device. In the embodiment illustrated, thelug 92 has been made integral with and extending from cover 33. A medialportion 93 of an elongated traction wheel release lever or arm 94 issuperposed with respect to the lug 92. A

6 compression spring 95 at one end bears against the medial portion 93of said lever 94.

On its outer end portion, lever 94 has a handle 96 by which said arm orlever 94 can be gripped. At its inner end portion, the lever or arm 94is preferably enlarged to provide an elongated head 97, the longitudinalaxis of which extends transversely of the longitudinal axis of the leveror arm 94, as illustrated in FIG. 2. By means of fasteners 98, such asbolts or the like, which extend through the opposite end portions of thehead 97, the lever 94 is tied to, and connects together, the hearing orrotor flange '78 and the rotor 71. As illustrated in FIG. 3, head 97 iseccentrically disposed.

When the reversible motor 11 is in the feed portion of its cycle, thedriving force is transmitted through the spiroid input pinion 12 to thespiroid gear head 14 which is carried by said pinion. The spiroid gearhead 14, by reason of its mesh with the external worm or spiroid gear44, causes the gear 44 to rotate counterclockwise in the bore 41 as seenin FIGS. 1, 2 and 4.

The counterclockwise torque of the gear 44 is transmitted to planet gear55 by reason of the meshing of the teeth 53 and 54; and accordingly gear55 is set in counterclockwise rotation about its axis of rotation.Additionally, the torque of the gear 44- tends to revolve gear 55 aboutthe axis of rotation of the gear 44.

The torque tending to revolve the spur planet gear 55 about the axis ofgear 44 is transmitted to the rotor 71 and its flange in which the shaft56 of said gear 55 is mounted. Thereby, rotor 71 and flange 73 tend torotate counterclockwise with respect to FIGS. 1, 2 and 4.

The counterclockwise torque of the rotor 71 will cause traction wheel 57to be revolved about the axis of gear 44 which is the same as the axisof rotation of rotor 71. Such motion carries traction wheel 57 away fromback up wheel 69. However, the counterclockwise torque of rotor 71 istranslated into a counterclockwise rotation of the lever 94 toward lug92 to compress the spring 95. The counterclockwise rotation of the arm94 is limited by the reaction of spring 95 tending to rotate the lever94 clockwise.

By predetermination in a manner well known in the art, spring 95 can beselected which will restrain rotation of the lever 94 at a point priorto the separation of the teeth 68 from the strapping S so that duringthe feeding portion of the cycle, strapping S is positively driven byteeth 68, when rotating in a counterclockwise direction with respect toFIGS. 1, 2 and 4. With the feeding torque thus balanced by the forceresisting compression of the spring 95, rotor 71 is thus held in asubstantially fixed position. Accordingly, the spur planet gear 55 willbe unable to revolve about the axis of rotation of the spiroid gear 44and rotor 71, and therefore said planet gear will merely rotate idlyabout its axis of rotation.

Having described the manned in which the traction wheel 57 will tend tomove away from back up roller 69, it is appreciated that when strap S isfor the first time threaded through the device, or when it must bereplaced or positioned for operation, sufficient manual force applied tothe handle 96 will compress the spring 95 sufliciently to permitrotation of rotor 71 counterclockwise a distance great enough toseparate the toothed traction wheel 57 and the back up wheel 69.Thereupon, strap S may be passed easily between the opposed wheels 57and 69.

Once the feeding of the strap S has been completed and the motor hasbeen reversed, removal of the slack from and tensioning of the strap Sensues prior to sealing and segmentation thereof. With reference to FIG.1, strap S moves downwardly during tensioning; and the tensioning torqueis clockwise with respects to FIGS. 1, 2 and 4. As the tensioningoperation proceeds, the force required to tension the strap S increasesby reason of the increasing resistance to tensioning which is built upin the strap. Such increasing demand for force is supplied in accordancewith the heretofore described construction by means comprising thespiroid gear 44 which is caused to rotate clockwise with respect toFIGS. 1, 2 and 4, by prime mover 11. Such clockwise rotation causes spurplanet gear to also rotate clockwise about its axis of rotation.However, in addition the spur planet gear 55 tends to revolve clockwiseabout the axis of rotation of the gear 44. This torque complementedpartially by the normal expansion of the spring 95 tends to rotate therotor 71 clockwise as well as the arm 94 to which said rotor is secured.

Inasmuch as the axis of rotation for the arm 94 and the rotor oreccentric 71 is the axis of rotation for gear 44, the shaft 56 carriedin the eccentric opening 72 will be revolved about the axis of gear 44and moved toward the fixed shaft 70 of the back up wheel 69. Suchmovement of the shaft 56 carries with it the traction wheel 57 whichaccordingly will move toward the back up wheel 69 and thereby causeprogressive embedding of the teeth 68 in and increasing gripping andtensioning force applied on the strap S.

Referring now to the modified form of the strap feeding and tensioningmechanism seen in the drawings in FIGS. and 6, the traction wheel 157 issecured on shaft section 156 which is part of the shaft 112 and whichprovides an axis for rotation for said traction wheel 157. To effectuatethe mounting of the traction wheel 157, a plurality of grooves 155 areprovided in the outer end portion 154 of the shaft 156. The grooves 155extend longitudinally of said shaft 156 and have mounted thereinlongitudinal splines 153 of a spline means 152. Fasteners such as socketor countersunk screws 15-1 rigidly secure the spline means 152 to theouter end portion 154 of the shaft 156.

At their inner end portions the spline means 152 have enlarged integralkeys 158 which extend outwardly from the slot or grooves 155. Thetraction wheel 157 has a plurality of inner keyways 159 in which keys158 are disposed to lock the traction wheel 157 on the shaft 156 fromindependent rotation with respect to said shaft.

The traction wheel 157 is restrained from displacement longitudinally ofthe shaft 156 by means of a pair of annular spacers 148 and 149 whichare disposed about shaft end portion 154 in spaced relationshiplongitudinally of the shaft 156. The inner face of the spacer 148 bearsagainst the outer flat 147 of the traction wheel 157. The outer face ofthe spacer 148 bears against an annular race of bearing 146. The outerface of the inner spacer 149 bears against the inner flat 145 oftraction wheel 157. The inner face of the spacer 149 bears against theannular race of bearing 150.

The shaft 156 is journalled in the bearing members 146 and 150, in themanner illustrated in the drawings. The means providing for retention ofthe bearings 146 and 150 will be hereinafter described.

The shaft 156 is operably connected to and has the same axis of rotationas drive shaft 112 which is rotatably driven by the prime mover. In themodified embodiment being described the prime mover is a reversible airmotor characterized by a housing 111 which tends and is free to rotatein a direction opposite the normal torque of the shaft 112 in proportionto the resistance to rotation of said shaft. Accordingly therefore, whenthe shaft 156, which rotates clockwise with respect to FIG. 5 during thestrap tensioning operation, tends to stall because of insufiicienttorque, the housing 111 will be caused to rotate counterclockwise.

Housing 111 has an annular flange 1 1 3 which is centrally apertured toaccommodate the drive shaft 112. The flange 113 is rigidly connected bymeans of fasteners such as bolts or the like 114 to the radiallyextending flange 115 of a motor mount or bushing generally designated bythe numeral 116.

The motor mount or bushing 116 has an integral annular outwardlyextending journalling extension, eccentric portion or rotor 171 whichhas an eccentric passage or bore 172 common with the central bore of theflange 115. Thereby flange is concentric with said bore 172, and therotor or eccentric journalling extension 171 is disposed eccentricallywith respect to flange 115 and said bore 172, as illustrated in thedrawings in FIGS. 5 and 6. Accordingly, the shaft 156 is centrallydisposed with respect to the flange 115, but it is eccentricallydisposed with respect to the rotor or eccentric 171.

Bore 172 is enlarged to provide an annular shoulder 173 against whichouter peripheral portion of the central race of the ball bearing 1'50abuts. A retaining ring 175 seated in groove 176 formed in the centralsurface of flange 115 bears against the opposite face of the peripheralrace of the bearing 150 to complete the retention of said bearing.

The frame 110 to accommodate the modification illustrated in FIGS. 5 and6, is provided with a passage or bore 118 which is circular in crosssection and which extends longitudinally of the shaft 156. A pair ofannular bushing or bearing liners 117 and 119, fabricated from anysuitable bearing material such as bronze and the like, are suitablymounted in the bore 118 in spaced apart relationship longitudinally ofrotor 17 1.

Bushing 117 has an inner radial flange 120 which extends outwardly fromthe bore 118 between a portion of the frame 110 and the forward face ofthe radial flange 115 to provide a bearing between said flange 115 andthe frame 110, as illustrated in FIG. 6. Bushing 119 has an integralouter radial flange 121 which extends outwardly from bore 118 andprovides a bearing between the frame 110 and a motor mount flange orring 122. The medial or axially extending portion 127 of the annularbushings 117 and 119 provide the bearing for rotation of the rotor oreccentric 171 within the frame aperture 118, as illustrated in thedrawings.

The motor mount flange 122 is disposed in a well 123 which comprises anouter end extension of the bore 118 having an enlarged diameter toaccommodate said ring 122. The width of the motor mount flange 122permits an inner annular portion 124 thereof to cover the outer end faceof an outer peripheral portion 125 of the rotor 1711 to which said ringis secured by means of a plurality of fasteners such as screws or thelike 126, as illustrated in the drawings.

Accordingly, it is seen that the flange 115 retains the assembly fromoutward movement or displacement, and the flange or ring 122 retains theassembly from inward movement or displacement.

A bearing cap generally designated as 128 is mounted centrally of themotor mount flange 122. Said cap 128 covers the outer end of the opening172 and has a radial flange 129 which is disposed against the outer faceof the centerward portion 130 of the rotor 171. By means of fastenerssuch as screws or the like 177, and a grease fitting 131, two of whichare seen in FIG. 5, the bearing cap 128 is secured to said rotor 171.

Bearing cap 128 has an inwardly extending elongated axial eccentricflange 132, the outer diameter of which is substantially the same as theinner diameter of the rotor 171 or of the bore 172. Flange 132 isdisposed against the inner face of rotor 171 whereby the radius of saidbore 172 is reduced by the thickness of the radial flange 132, asillustrated in FIG. 6. Within said bore 172 the flange 132 is disposedabout an outer end portion 154 of the shaft 156.

A retaining ring 133 mounted in an annular groove provided therefore inthe inner surface of the wall of the flange 132 bears against theperipheral portion of the race of bearing 146, as illustrated in FIG. 6.Said retaining ring 133 together with the spacer 148 preclude inwardmovement of the bearing 146. Outward movement or displacement of thebearing 146 is precluded by the abutment of the outer surface of theperipheral race of bear- 9 ing 146 with the shoulder 134 generated inthe inner surface of the flange 132, as illustrated in FIG. 6.

A traction wheel release lever or arm 194 having at the outer endportion thereof a hand grip 196 has its inner end portion 193 suitablysecured such as welding 174 or the like to a flat plate or leveranchoring member 197, as illustrated in the drawings. The inner flat ofplate 197 is disposed against the outer surface of bearing cap 128 towhich it is secured by means of fasteners such as screws 177. Screws 177also tie plate 197 to rotor 171 and bearing cap 128 to rotor 171.

Back up wheel or pressure roller 169 is rotatable about a fixed axisprovided by a shaft 170 to which said back up wheel or pressure roller169 is rigidly secured or fixed.

As illustrated in FIG. 5, a peripheral portion of the flange 115 is cutaway to provide a shoulder flat 190 from which there extends a dowel orpin 191. A pin or bolt 192 is rigidly secured in the frame 110 in axialalignment with the dowel 191. The bolt 192 carries a collar 193 adaptedto be adjusted longitudinally of the bolt 192 in any suitable fashion,as for example by an adjusting nut 195. A compression spring 198 ismounted about the bolt 192 and the pin 191 with one end of said springbearing against the end face 199 of said bolt 193 and the other end ofsaid spring bearing against the shoulder 190 in position disposed aboutsaid pin 191. When the spring 198 is under compression it exerts itsforce against flange 115 and thereby tends to rotate the motor mount 116counterclockwise about the center of rotation of rotor 171.

By pushing the handle 196 downwardly, that is rotating it clockwiseabout its connection with plate 197, rotor 171 will rotate clockwise.Traction wheel 157 will be revolved about the center of rotation of therotor 171 and thereby be carried slightly away from the back up wheel orpressure roller 169 and permit the initial positioning of the strap SSbetween said traction wheel 157 and back up wheel 169. Such initialrotation will compress the spring 198. Upon release of the handle thespring 198 will decompress and will rotate rotor 171 counterclockwiseand carry the traction wheel 157 back to its normal starting positionwith respect to the back up wheel 169.

The strap SS will then be fed until a desired length thereof is inposition around the article to be tied and during such feeding thetraction wheel 157 will rotate counterclockwise with respect to FIG. 5.

Because of its load the spring 198 will not have any effect on theposition of the motor mount 116 except to the extent that it willovercome any tendency of housing 111 and accordingly motor mount 116, torotate clockwise during the feeding operation. However, as there is nosubstantial resistance to the rotation of the traction wheel 157 duringthe feeding operation, the input energy to the prime mover will betranslated into counterclockwise rotation of the shaft 112, and thereforthe shaft 156, to drive the traction wheel 157. Under such conditionsthere will be virtually no movement of the motor mount 116.

After the desired amount of strap SS has been fed, the drive of theprime mover will be reversed in a manner heretofore described forreversal of the drive. Thereupon, the tensioning operation commences andaccordingly, the traction wheel 157 will be driven clockwise withrespect to FIG. 5, with a resultant strap movement to the right.

As the tensioning increases, the resistance thereto in the strap SSincreases, with the resultant requirement of more torque in the tractionwheel 157 to move the strap SS in the tensioning direction. As theresistance to the tensioning increases, the shaft 156 and the tractionwheel 157 carried thereby will slow down and tend to stall with acorresponding action set up in the motor shaft 112 with a resultantbuild up of torque.

A reaction occurs in housing 111 with the input energy for the primemover translated into a torque tending to 10 rotate motor housing 111counterclockwise with respect to FIG. 5. The degree of the reaction isproportional to the slowing down of the rotation and increase in torqueon the shaft 156 caused by the drag resulting from the resistance to thetensioning.

As the motor housing 111 rotates, it carries with it the mot-or mount116 and the integral eccentrically bored rotor or eccentric 171 in whichthe shaft 156 is journalled. Rotation of the motor mount is about anaxis defining the center of the rotor or eccentric 171 and extendinglongitudinally thereof. With respect to FIG. 5 therefore, it isappreciated that the counterclockwise rotation of the rotor 171 willrock traction wheel 157 counterclockwise about the axis of rotation ofrotor 171 to carry traction wheel 157 into closer engagement with ortoward back up wheel or roller 169 to more forcefully grip the tensionedstrap and exert a greater tensioning force thereupon. Accordingly, asthe shaft 156 again beg-ins to rotate clockwise, as it overcomes theresistance in the tensioned strap SS, the tendency of the eccentric 171to rotate or rock counterclockwise will diminish in proportion to theovercoming of the resistance in the strap SS.

From the foregoing it is appreciated that the herein describedtensioning mechanisms are capable of self energization in accordancewith the torque requirements to tension the strap undergoing tensioningand in which the resistance to such tensioning is gradually increasing.Furthermore, because of the mechanical advantage inherent in thedescribed construction, rapid building of torque applied to thetensioned strap is insured. Inasmuch as the mechanical advantage isdetermined by the moment between the axis of rotation of the rotor andthe axis of rotation of the traction wheel as well as the radius of thetraction wheel, variation thereof may be had from one device to another.

As many substitutions or changes could be made in the above describedconstruction, and as many apparently widely different embodiments of theinvention within the scope of the claims could be constructed withoutdeparting from the scope and spirit thereof, it is intended that allmatter contained in the accompanying specification shall be interpretedas being illustrative and not in a limiting sense.

I claim:

1. In a strapping machine for binding bundles and the like with a bandof tensioned strap, the combination of means providing a frame, primemover means, means for guiding strap through said frame, reversiblemeans for feeding strap through said guiding means and applying tensionto and shrinking such strap about a bundle, said reversible meansincluding a back up wheel rotatable on an axis of reaction and atraction wheel and rotatable shaft therefor between and by which strapis fed and tensioned in opposite directions, and a driven eccentricmovably connected to said prime mover means and rotatably mounting saidshaft to rotate about a floating axis and shift the traction wheeltowards and away from said back up wheel in accordance with the loadingimposed on the prime moving means in advancing the strap.

2. In a strapping machine for binding bundles and the like with a bandof tensioned strap and including prime mover means, and traction meansfor applying tension to and shrinking the strap about a bundle, saidtraction means including a back up wheel and a traction wheel and shafttherefor between and by which the strap is advanced, the subcombinationof means for controlling force application on the strap by said tractionmeans comprising a rotatable rotor housing rotatably connected to saidprime mover means, a rotor journalled within said rotor housing, saidshaft disposed eccentrically in said rotor, and force transmission meansfor transmitting the rotational force of said rotor housing to saidrotor in a loading direction to shift said shaft for moving the tractionwheel closer to the back up wheel as tension on the strap is increased.

3. In a strapping machine in accordance with claim 2 and spring meansyieldingly resisting rotation of the rotor in the loading direction.

4. In a strapping machine for binding bundles and the like with a bandof tensioned strap, the combination of means providing a frame, primemover means, means for guiding binding strap through said frame,reversible means for feeding strap through said guiding means andapplying tensioning to and shrinking such strap about a bundle, saidreversible means including a back up wheel rotatable on a first fixedaxis and a traction wheel and rotatable shaft therefor between and bywhich binding strap is fed and tensioned in opposite directions, with adriven rotor rotatably connected to said prime mover means, said rotorhaving an opening disposed eccentrically from its axis of rotation, saidshaft journalled in said opening; and means for intermittently drivingsaid rotor whereby the gripping force of said back up wheel and tractionwheel is varied during tensioning.

5. In a strapping machine for binding bundles and the like with a bandof tensioned strap, the combination of means providing a frame, primemover means, means for guiding strap through said frame, reversiblemeans for feeding strap through said guiding means and applyingtensioning to and shrinking such strap about a bundle, said reversiblemeans including a backup wheel rotatable on an axis of reaction and atraction wheel and rotatable shaft therefor between and by which bindingstrap is fed and tensioned in opposite directions, with a driven rotorrotatably connected to said prime mover means, said rotor having anopening disposed eccentrically from its axis of rotation, said shaftjournalled in said eccentric opening whereby spacing of said back upwheel and traction wheel is varied, and means limiting the rotation ofsaid rotor.

6. In a strapping machine for binding bundles and the like with a bandof tensioned strap, the combination of means providing a frame, a primemover, means for guiding strap through said frame, and reversible meansfor feeding strap through said guiding means and applying tension to andshrinking such strapping about a bundle, said reversible means includinga back up wheel rotatable on a fixed axis and a traction wheel and shafttherefor between and by which strap is fed and tensioned in oppositedirections, with rotor housing in said frame, a rotor mounted in saidhousing about a fixed axis of rotation, said shaft eccentricallyjournalled in said housing; means connected to said prime mover forrotating said rotor and means connected to said prime mover for drivingsaid shaft whereby the traction wheel rotates in positions adjustablyspaced from said back up wheel.

7. In a strapping machine for binding bundles and the like with a bandof tensioned strap, having means providing a frame, prime mover means,means for guiding strap through said frame, and reversible means forfeeding strapping through said guiding means and applying tension to andshrinking such strap about a bundle, said reversible means including aback up Wheel rotatable on a fixed axis and a traction wheel and shafttherefor between and by which strap is fed and tensioned in oppositedirections, the subcombination of means for controlling force applied onstrap by said reversible means comprising a driven internal gear memberrotatably connected to said prime mover means; a planet gear driven byand rotating on an axis eccentric to said internal gear member, saidplanet gear secured to said shaft, whereby the traction wheel is movedto and away from said back up wheel.

8. In a strapping machine for binding bundles and the like with a bandof tensioned strap, having means providing a frame, prime mover means,means for guiding strap through said frame, and reversible means forfeeding strap through said guiding means and applying tension to andshrinking such strapping about a bundle, said reversible means includinga back up wheel rotatable on a fixed axis and a traction wheel and shafttherefor between and by which strap is fed and tensioned in oppositedirections, the subcombination of means for controlling force applied onstrap by said reversible means comprising a driven gear ring rotatablyconnected to said prime mover means and disposed about said shaft; aplanet gear driven by and disposed eccentrically with said gear ring,said planet gear secured to said shaft; a pivoted lever operablyconnected to said shaft, and means for pivoting said lever partially torevolve said shaft about the axis of rotation of said gear ring wherebythe gripping force of said back up wheel and traction wheel is adjusted.

9. In a strapping machine for binding bundles and the like with a bandof tensioned strap, having means providing a frame, prime mover means,means for guiding strap through said frame, and reversible means forfeeding strap through said guiding means and applying tension to andshrinking such strap about a bundle, said reversible means including aback up wheel rotatable on a fixed axis and a traction wheel and shafttherefor between and by which strap is fed and tensioned in oppositedirections, the subcombination of means for controlling force applied onstrap by said reversible means comprising a driven ring gear rotatablyconnected to said prime mover means and disposed about said shaft; aplanet gear eccentrically disposed within and driven by said ring gear,said planet gear secured to said shaft; a pivoted lever operablyconnected to said shaft; means for driving said shaft partially aboutthe axis of rotation of said ring gear and a spring bearing against aportion of said lever whereby separation of said back up wheel andtraction wheel is limited during strap feeding.

10. In a strapping machine for binding bundles and the like with a bandof tensioned strap, having means providing a frame, prime mover means,means for guiding strap through said frame, and reversible means forfeeding strap through said guiding means and applying tension to andshrinking such strap about a bundle, said reversible means including aback up wheel rotatable on a fixed axis and a traction wheel and shafttherefor between and by which strap is fed and tensioned in oppositedirections, the subcombination of means for controlling force applied onstrap by said reversible means comprising a driven ring gear rotatablyconnected to said prime mover means and disposed about said shaft; aplanet gear driven by and eccentrically disposed within said ring gear,said planet gear secured to said shaft; a driven rotor, said shafteccentrically journalled in said rotor; a lever operable connected tosaid rotor, and a spring bearing about an outer portion of said leverwhereby as said shaft rotates in one direction said spring holds saidlever and rotor from pivoting and as said shaft rotates in an oppositedirection said lever is pivoted and causes said rotor to rotate.

11. In a strapping machine for binding bundles and the like with a bandof tensioned strap, having means providing a frame, prime mover means,means for guiding strap through said frame, and reversible means forfeeding strapping through said guiding means and applying tension to andshrinking such strap about a bundle, said reversible means including aback up wheel rotatable on an axis of reaction and a traction wheel andshaft therefor between and by which strapping is fed and tensioned inopposite directions, the subcombination of means for controlling forceapplied on strap by said reversible means comprising a rotatable rotorhousing rotatably connected to said prime mover means, a rotorjournalled within said rotor housing, said shaft disposed eccentricallyin said rotor, and force transmission means for transmitting therotational force of said rotor housing to said rotor, whereby saidtraction wheel is moved toward and away from said back up wheel.

12. In a strapping machine for binding bundles and the like with a bandof tensioned strap, having means providing a frame, prime mover means,means for guiding strap through said frame, and reversible means forfeeding strap through said guiding means and applying tension to andshrinking such strap about a bundle, said reversible means including aback up wheel rotatable on a fixed axis and a traction wheel and shafttherefor between and by which strap is fed and tensioned in oppositedirections, the subcornbination of means for controlling force appliedon strapping by said reversible means comprising a rotatable rotorhousing rotatably connected to said prime mover means, a rotorjournalled in said housing and having an eccentric opening, said shaftjournalled in said opening; a force transmission link operably connectedto said shaft and driven by said rotor housing, and a spring biasedlever connected to said rotor and thereby controlling the relativedisposition of said rotor within said housing and the traction wheelsecured to said shaft.

13. In a strapping machine for binding bundles and the like with a bandof tensioned strap, having means providing a frame, means for guidingstrap through said frame, and reversible means for feeding strap throughsaid guiding means and applying tension to and shrinking such strapabout a bundle, said reversible means including a back up wheelrotatable on a fixed axis and a traction wheel and shaft thereforbetween and by which strap is fed and tensioned in opposite directions,the subcombination of means for controlling force applied on strap bysaid reversible means comprising a rotor rotatable about a fixed axis insaid frame and disposed about said shaft; a motor, the stator of saidmotor operably connected to said rotor, said motor operably connected tosaid shaft, whereby as said shaft tends to stop, said rotor tends torotate and thereby move the traction wheel to and away from said back upwheel.

14. In a strapping machine for binding bundles and the like with a bandof tensioned strap, having means providing a frame, means for guidingstrap through said frame, and reversible means for feeding strap throughsaid guiding means and applying tension to and shrinking such strapabout a bundle, said reversible means including a back up wheelrotatable on a fixed axis and a traction wheel and shaft thereforbetween and by which strap is fed and tensioned in opposite directions,the subcombination of means for controlling force applied on strap bysaid reversible means comprising a rotor rotatable about a fixed axis insaid frame, said rotor having an eccentric opening; said shaft disposedin said opening; a motor and rotatable housing therefor, said motorconnected to said shaft, said housing connected to said rotor, wherebyon slowing of said shaft said housing tends to rotate the rotor and movesaid shaft about the axis of rotation of said rotor.

15. In a strapping machine for binding bundles and the like with a bandof tensioned strap, having means providing a frame, means for guidingstrap through said frame, and reversible means for feeding strap throughsaid guiding means and applying tension to and shrinking such strapabout a bundle, said reversible means including a back up wheelrotatable on a fixed axis and a traction wheel and shaft thereforbetween and by which strap is fed and tensioned in opposite directions,the subcombination of means for controlling force applied on strap bysaid reversible means comprising a rotor rotatable about a fixed axis insaid frame, said rotor having an eccentric bore, said shaft journalledin said bore; a motor operably connected to said shaft; a motor housingrotatable reciprocally to, and about the axis of rotation of, the motorand connected to said rotor; and spring biased means operably connectedto said rotor,

14 whereby the traction wheel is urged toward said back up wheel.

16. In a strapping machine for binding bundles and the like with a bandof tensioned strap, having means providing a frame, means for guidingstrap through said frame, and reversible means for feeding strap throughsaid guiding means and applying tension to and shrinking such strapabout a bundle, said reversible means including a back up wheelrotatable on a fixed axis and a traction wheel and shaft thereforbetween and by which strap is fed and tensioned in opposite directions,the subcombination of means for controlling force applied on strap bysaid reversible means comprising a driven rotor journalled about a fixedaxis in said frame, said rotor having an eccentric bore; a motoroperably connected to said shaft, said shaft journalled in saideccentric bore; a motor housing secured to said rotor and adapted forrotation reciprocally to the rotation of said motor whereby as saidtraction wheel tends to stall during tensioning, said motor housingtends to rotate said rotor to revolve said shaft about the axis ofrotation of said rotor and change the position of the traction wheel.

17. In a strapping machine for binding bundles and the like with a bandof tensioned strap, having means providing a frame, means for guidingstrap through said frame, and reversible means for feeding strap throughsaid guiding means and applying tension to and shrinking such strapabout a bundle, said reversible means including a back up wheelrotatable on a fixed axis and a traction wheel and shaft thereforbetween and by which strap is fed and tensioned in opposite directions,the subcombination of means for controlling force applied on strap bysaid reversible means comprising a rotor journalled about a fixed axisin said frame, said shaft journalled in said rotor about an axiseccentric to the axis of rotation of said rotor, and a prime moverhaving reciprocally rotatable components operably connected to saidrotor and said shaft, respectively, and adapted to drive said shaft andsaid rotor in opposite directions, whereby as said shaft slows andtorque is increased during tensioning the traction wheel is raisedtoward said back up wheel.

18. In a strapping machine for binding bundles and the like with a bandof tensioned strap, the combination of means providing a frame, primemover means, means for guiding binding strap through said frame,reversible means for feeding strap through said guiding means andapplying tensioning to and shrinking such strap about a bundle, saidreversible means including a back up wheel rotatable on an axis ofreaction and a traction wheel and rotatable shaft therefor between andby which binding strap is fed and tensioned in opposite directions, witha driven rotor rotatably connected to said prime mover means, said shaftjournalled in said rotor; means for partially rocking the shaft aboutthe axis of rotation of said rotor whereby the spacing of said back upWheel and traction wheel can be varied and means for limiting therotation of said rotor.

References Cited by the Examiner UNITED STATES PATENTS 2,215,121 9/1940Harvey et al. l0026 X 2,438,386 3/1948 Chamberlain -29 X 2,915,00312/1959 Crosby et al. l0026 2,915,004 12/1959 Leslie 100-26 3,023,6933/1963 Crosby et al. 10032 3,086,451 4/1963 Van der Wal 10026 3,088,3975/1963 Martin et al. 10026 WALTER A. SCHEEL, Primary Examiner.

BILLY J. WILHITE, Examiner.

1. IN A STRAPPING MACHINE FOR BINDING BUNDLES AND THE LIKE WITH A BANDOF TENSIONED STRAP, THE COMBINATION OF MEANS PROVIDING A FRAME, PRIMEMOVER MEANS, MEANS FOR GUIDING STRAP THROUGH SAID FRAME, REVERSIBLEMEANS FOR FEEDING STRAP THROUGH SAID GUIDING MEANS AND APPLYING TENSIONTO AND SHRINKING SUCH STRAP ABOUT A BUNDLE, SAID REVERSIBLE MEANSINCLUDING A BACK UP WHEEL ROTATABLE ON AN AXIS OF REACTION AND ATRACTION WHEEL AND ROTATABLE SHAFT THEREOF BETWEEN AND BY WHICH STRAP ISFED AND TENSIONED IN OPPOSITE DIRECTIONS, AND A DRIVEN ECCENTRIC MOVABLYCONNECTED TO SAID PRIME MOVER MEANS AND ROTATABLY MOUNTING SAID SHAFT TOROTATE ABOUT A FLOATING AXIS AND SHIFT THE TRACTION WHEEL TOWARDS ANDAWAY FROM SAID BACK UP WHEEL IN ACCORDANCE WITH THE LOAD-